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Recent advances in annulations enabled by nucleophilic Lewis base/metal dual catalysis

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Chinese Chemical Letters 2023年第10期34卷 12-26页

作者： Qian Wang Yinggao Meng Lulu Wu er-qing li College of Chemistry Green Catalysis CenterZhengzhou UniversityZhengzhou 450001China School of Science Henan Agricultural UniversityZhengzhou 450002China

Metal/nucleophilic Lewis base dual catalysis has been recognized as a reliable and promising strategy for finishing ideal organic synthesis over the past *** new strategy can usually achieve some chemical reactions that cannot be realized by the traditionally mono-catalytic system,dramatically expanding the synthetic utility of chemical transformations by leveraging additional activation *** considerable progress has been made in the synthesis of a wide range of heterocyclic and biologically active compounds by using the combination of diversely metal/nucleophilic Lewis base dual catalysts,including metal/phosphine,metal/N-heterocyclic carbene(NHC)and metal/tertiary amine dual catalysis *** this review,we describe a comprehensive and updated advance of metal/nucleophilic Lewis base dual catalytic annualtion reactions,meanwhile,the related mechanism and the application of these annulation strategies in natural product total synthesis will be highlighted in detail.

关键词： Lewis base Metal catalysis Annualtion Dual catalysis Synthetic methods

Diastereodivergent synthesis of fully disubstituted spiro[indoline-3,2’-pyrrolidin]-2-ones via tuneable Lewis base/Brønsted base-promoted(3+2)cycloadditions

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Organic Chemistry Frontiers 2022年第1期9卷 19-24页

作者： Ke li Zhipeng Zhang Jiahui Zhu Yuxin Wang Jing Zhao er-qing li Zheng Duana College of Chemistry Green Catalysis CenterInternational Phosphorus LaboratoryInternational Joint Research Laboratory for Functional Organophosphorus Materials of Henan ProvinceZhengzhou UniversityZhengzhou 450001P.R.China Xuchang Environmental Monitoring Center Henan ProvinceP.R.China

Herein we report a diastereodivergent synthesis of fully disubstituted spiro[indoline-3,2’-pyrrolidin]-2-ones through base-promoted(3+2)***,the catalysts are found to have full control over the configuration of the *** a Lewis base(PCy3)is used as a catalyst,good yields and excellent diastereoselectivities are obtained,regardless of the properties of the substituents,whereas spiro[indoline-3,2’-pyrrolidin]-2-ones of a different diastereoisomer are produced in good yields when a Brønsted base(K_(2)CO_(3))is ***-MS experiments proved the existence of key zwitterionic intermediates.

关键词： base stereo substituted

Effect of pyrite content on chalcopyrite flotation under different regrinding conditions

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 49-57页

作者： Zejun Wang qing Shi Guofan Zhang Yuxuan Zhu Binbin li School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

This study aimed to investigate the effect of varying pyrite(Py)content on copper(Cu)in the presence of different regrinding conditions,which were altered using different types of grinding media:iron,ceramic balls,and their mixture,followed by flotation in the cleaner *** flotation performance of rough Cu concentrate can be improved by changing the regrinding conditions based on the Py *** electron microscopy,X-ray spectrometry,ethylenediaminetetraacetic acid disodium salt extraction,and X-ray photoelectron spectroscopy studies illustrated that when the Py content was high,the use of iron media in regrinding promoted the generation of hydrophilic Fe OOH on the surface of Py and improved the Cu *** ceramic medium with a low Py content prevented excessive Fe OOH from covering the surface of chalcopyrite(Cpy).Electrochemical studies further showed that the galvanic corrosion current of Cpy-Py increased with the addition of Py and became stronger with the participation of iron media.

关键词： chalcopyrite regrinding media pyrite galvanic corrosion flotation

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企业并购文化整合的演化博弈及动态仿真研究

软科学 2017年第3期31卷 42-48页

作者：李天博齐二石李青天津大学管理与经济学部天津300072 中国汽车技术研究中心认证中心天津300300 天津职业技术师范大学汽车与交通学院天津300222

在明确企业并购文化整合运行模式的基础上,构建了考虑两方群体策略的文化整合演化博弈模型,并提出不同参数条件下的群体策略发展规律。采用系统动力学的方法,建立企业并购文化整合的SD仿真模型,对比分析各因素变化对演化结果的影响。研... 详细信息

在明确企业并购文化整合运行模式的基础上,构建了考虑两方群体策略的文化整合演化博弈模型,并提出不同参数条件下的群体策略发展规律。采用系统动力学的方法,建立企业并购文化整合的SD仿真模型,对比分析各因素变化对演化结果的影响。研究结果表明:群体初始策略比例、改变文化成本、改变文化超额效用和抵制文化改变风险对博弈双方的演化策略具有显著影响,制定合适的文化整合方案,需要着重考虑上述因素。

关键词：企业并购文化整合演化博弈系统动力学

Modular assembly of Co4-thiacalix[4]arene units and Keggin-type SiW12O40 for visible-light photothermal conversion

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Tungsten 2025年第1期7卷 112-119页

作者： Jia-Hui li qing Zhao Dong-Ao Mao Kun Zhou Bao-Kuan Chen Yan-Feng Bi School of Petrochemical Engineering Liaoning Petrochemical University

The construction of metal-organic coordination clusters（MCCs） using modular secondary building units is an important method for preparing functional *** this study,two new MCCs modularly assembled from Keggin-type {SiW12O40}H4TC4A=p-tert-Butylthiacalix[4]arene(SiW12) units and thiacalixarene-supported Co4-thiacalix[4]arene(Co4-TC4A polynuclear second-building units（PSBUs,H4TC4A=p-tert-Butylthiacalix[4]arene） are *** two MCCs,abbreviated as Co4-SiW12and Co8-SiW12,were structurally characterized by single-crystal X-ray *** Co4-SiW12is a supramolecular structure involving cation-anion interactions between Co4-TC4A PSBUs and ***8-SiW12features "barbell-like" shapes with two Co4-TC4A coordinatively linked to a Keggin-type SiW12unit on opposite via W-O_t-Co *** coordination of Co4-TC4A to SiW12in Co8-SiW12resulted in significantly improved photothermal conversion performances compared with Co4-SiW12and pure SiW12or ***-gap determination and photophysical analysis combined with density functional theory calculations indicated the binding mode between Co4-TC4A PSBUs and SiW12,which considerably influences the way of electron transport and the conversion ability of visible light to heat.

关键词： Modular construction Photothermal conversion Polyoxometalate Thiacalixarene

Trinuclear gold-catalyzed site-selective alkylation of peptides

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Science China Chemistry 2025年第1期68卷 249-256页

作者： qing-Yun Fang Chengyihan Gu Yinghan Chen Wencheng Yan Yong liang Weipeng li Chengjian Zhu Jie Han Jin Xie State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic Materials Chemistry and Biomedicine Innovation Center (Chem BIC) School of Chemistry and Chemical Engineering Nanjing University Green Catalysis Center College of Chemistry Zhengzhou University State Key Laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging issue. The selective alkylation of peptides can alter the biological activity and physical properties of molecules, and it has gained significant research interest. We herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis. A wide range of structurally diverse primary, secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of peptides. This protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups. A series of relay transformations to construct cyclic peptides, to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic practicality. In addition, mechanistic studies and density functional theory(DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer(SET) mechanism.

关键词： gold catalysis peptide alkylation C-C coupling radical

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Plasmonic tandem heterojunctions enable high-efficiency charge transfer for broad spectrum photocatalytic hydrogen production

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Journal of Energy Chemistry 2025年第1期100卷 710-720页

作者： Wenxuan Chen Xiu-qing Qiao Guo Hui Bojing Sun Dongfang Hou Meidi Wang Xueqian Wu Tao Wu Dong-Sheng li College of Materials and Chemical Engineering Key Laboratory of Inorganic Nonmetallic Crystalline and Energy Conversion Materials China Three Gorges University Hubei Three Gorges Laboratory College of Chemistry and Materials Science and Guangdong Provincial Key Laboratory of Supramolecular Coordination Chemistry Jinan University

Rational engineering of semiconductor photocatalysts for efficient hydrogen production is of great significance but still challenging,primarily due to the limitations in charge transfer ***,a fascinating plasmonic tandem heterojunction with the hc-CdS/Mo2C@C heterostructure is aimfully prepared for effectively promoting the charge separation kinetics of the CdS photocatalyst via the synergistic strategy of phase junction,Schottky junction,and photothermal *** difference in atomic configuration between cubic-CdS （c-CdS） and hexagonal-CdS （h-CdS） leads to effective charge separation through a typical Ⅱ charge transfer mechanism,and plasmonic Schottky junction further extracts the electrons in the hc-CdS phase junction to realize gradient charge ***,the photothermal effect of Mo2C@C helps to expand the light absorption,accelerate charge transfer kinetics,and reduce the hydrogen evolution energy *** carbon layer provides a fast channel for charge transfer and protects the photocatalyst from *** a result,the optimized hc-CMC photocatalyst exhibits a significantly high photocatalytic H2production activity of 28.63 mmol/g/h and apparent quantum efficiency of 61.8%,surpassing most of the reported *** study provides a feasible strategy to enhance the charge transfer kinetics and photocatalytic activity of CdS by constructing plasmonic tandem heterogeneous junctions.

关键词： Cadmium sulfide

The complex roles of m^(6)A modifications in neural stem cell proliferation, differentiation, and self-renewal and implications for memory and neurodegenerative diseases

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Neural Regeneration Research 2025年第6期20卷 1582-1598页

作者： Yanxi li Jing Xue Yuejia Ma Ke Ye Xue Zhao Fangliang Ge Feifei Zheng Lulu liu Xu Gao Dayong Wang qing Xia Department of Biochemistry and Molecular Biology College of Basic Medical SciencesHarbin Medical UniversityHarbinHeilongjiang ProvinceChina College of Basic Medical Sciences Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Basic Medical Institute Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Key Laboratory of Heilongjiang Province for Genetically Modified Animals Harbin Medical UniversityHarbinHeilongjiang ProvinceChina Translational Medicine Research and Cooperation Center of Northern China Heilongjiang Academy of Medical SciencesHarbinHeilongjiang ProvinceChina Dongzhimen Hospital Beijing University of Chinese MedicineBeijingChina

N6-methyladenosine(m^(6)A), the most prevalent and conserved RNA modification in eukaryotic cells, profoundly influences virtually all aspects of mRNA metabolism. mRNA plays crucial roles in neural stem cell genesis and neural regeneration, where it is highly concentrated and actively involved in these processes. Changes in m^(6)A modification levels and the expression levels of related enzymatic proteins can lead to neurological dysfunction and contribute to the development of neurological diseases. Furthermore, the proliferation and differentiation of neural stem cells, as well as nerve regeneration, are intimately linked to memory function and neurodegenerative diseases. This paper presents a comprehensive review of the roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, as well as its implications in memory and neurodegenerative diseases. m^(6)A has demonstrated divergent effects on the proliferation and differentiation of neural stem cells. These observed contradictions may arise from the time-specific nature of m^(6)A and its differential impact on neural stem cells across various stages of development. Similarly, the diverse effects of m^(6)A on distinct types of memory could be attributed to the involvement of specific brain regions in memory formation and recall. Inconsistencies in m^(6)A levels across different models of neurodegenerative disease, particularly Alzheimer's disease and Parkinson's disease, suggest that these disparities are linked to variations in the affected brain regions. Notably, the opposing changes in m^(6)A levels observed in Parkinson's disease models exposed to manganese compared to normal Parkinson's disease models further underscore the complexity of m^(6)A's role in neurodegenerative processes. The roles of m^(6)A in neural stem cell proliferation, differentiation, and self-renewal, and its implications in memory and neurodegenerative diseases, appear contradictory. These inconsistencies may be a

关键词： Alzheimer's disease cell self-renewal central nervous system memory microglia nerve regeneration neurodegenerative diseases neurogenesis RNA methylation

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甜菜碱促进淡水白鲳生长的机制

水产学报 2003年第6期27卷 564-569页

作者：陆清儿李行先李忠全杭州市水产科学研究所杭州市水产科学研究所浙江杭州 310024

以淡水白鲳为试验对象,研究并探讨了盐酸甜菜碱促进淡水白鲳生长的机制。试验结果表明,盐酸甜菜碱能促进淡水白鲳生长,降低饲料系数,提高饲料利用率;在生理上,能提高血清中T3、胰岛素及血清白蛋白的含量,极显著降低血清中尿素氮的含量;... 详细信息

以淡水白鲳为试验对象,研究并探讨了盐酸甜菜碱促进淡水白鲳生长的机制。试验结果表明,盐酸甜菜碱能促进淡水白鲳生长,降低饲料系数,提高饲料利用率;在生理上,能提高血清中T3、胰岛素及血清白蛋白的含量,极显著降低血清中尿素氮的含量;组织切片图显示:甜菜碱可使小肠绒毛和傲绒毛高度、密度及分布均匀度明显提高,对肝细胞超微结构无不良影响。试验结果提示:甜菜碱使T3和胰岛素分泌增加,通过神经-内分泌水平调控机体代谢活动,实现其促进生长等功能,还使消化道形态产生有益的变化。

关键词：淡水白鲳生长盐酸甜菜碱